The agency said it is taking steps to add warnings about skin reactions to labels of over-the-counter medications containing acetaminophen, and it also will require prescription medications containing acetaminophen to include such warnings.

"This new information is not intended to worry consumers or health care professionals, nor is it meant to encourage them to choose other medications," Dr. Sharon Hertz, deputy director of FDA's Division of Anesthesia, Analgesia and Addiction, said in a statement. "However, it is extremely important that people recognize and react quickly to the initial symptoms of these rare but serious side effects, which are potentially fatal."

The FDA is adding the warning after reviewing cases of skin reactions linked to the medicine. Between 1969 and 2012, 107 cases of skin reactions linked to acetaminophen were reported to the FDA, which resulted in 67 hospitalizations and 12 deaths.

Two severe skin conditions linked to the medication are Stevens-Johnson Syndrome (SJS) and toxic epidermal necrolysis, in which the top layer of skin separates from the lower layers.

There is no way of predicting who is at higher risk for skin reactions while taking the medication. The FDA says it considers the benefits of the medication to outweigh the risks.